The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
All publications identified herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Magnetic fields and electromagnetic circuits can be used to change electrical energy into mechanical energy and vice-versa. The most versatile magnetic motors activate and deactivate magnetic fields in various ways.
U.S. Pat. No. 6,342,746 to Flynn teaches various permanent magnet devices magnetically coupled with pole pieces to provide multiple parallel magnetic flux paths. Control coils are positioned along flux paths and are energized in a variety of on/off programs to achieve desirable motive and static devices by manipulating flux paths within the pole pieces. However, Flynn's system merely activates and deactivates flux paths in parts of the pole pieces, which prevents full utilization of Flynn's pole pieces when a flux path is deactivated.
U.S. Pat. No. 6,518,681 to Ogino teaches a motor that improves energy efficiency by arranging permanent magnet elements on both sides of an electromagnet element through contact surfaces, such that the working surfaces and the contact surfaces are held opposite to each other through the permanent magnet element. Such a configuration allows the electromagnet element to shift the working surfaces from a first state where the permanent magnet's magnetic line of force goes round along a closed magnetic path of the electromagnet element to a second state where the permanent magnet's magnetic line of force is discharged into the air, allowing the magnetic flux force to affect an attraction member from a distance. Ogino's motor, however, only affects attraction members in one state, effectively turning it into an “on-off” device, which fails to utilize the attractive force of the permanent magnet when the motor is in its “off” state.
U.S. Pat. No. 7,453,341 to Hildenbrand teaches a valve comprising both a permanent magnet and an electromagnet comprising a bore and a coil. Hildenbrand's valve aligns the poles of the permanent magnet and the electromagnet to create a combined magnetic field on a load when the electromagnet is turned on, and the magnetic field returns to its original magnetic flux path away from the load and through the electromagnet bore when the electromagnet is turned off. While Hildenbrand combines the magnetic fields of both the permanent magnet and the electromagnet into a single force, Hildenbrand's effective pole can only act upon a load when the electromagnet is turned on, which would normally be only 50% of the time when used in an electromagnetic rotor.
Thus, there remains a need for a system and method that fully utilizes the flux energy from permanent magnets and electromagnetic devices in all states.